CODEWITHSUNDEEP
pythontkinternameerrortkinter-entry
Clayton Keleher
Clayton Keleher

Reputation: 165

Can't refer to an Entry field inside a class?

I'm trying to set a global variable to the value entered into a Tkinter Entry field, but I'm getting the following error:

NameError: global name 'HealthEntry' is not defined

Here's the relevant code:

Health = 0

class window(Tk):
    def __init__(self, parent):
        Tk.__init__(self, parent)
        self.parent = parent

        HealthEntry = Entry(self)

        testButton = Button(self, text = "entry field test", command = self.printHealth)
        testButton.grid(row=18, column=3)

    def printHealth(self):
        Health = HealthEntry.get()
        print Health

I've also tried changing HealthEntry.get() to window.HealthEntry.get(), but that doesn't work either. What am I doing wrong?

Upvotes: 1

Views: 50

Answers (2)

omri_saadon
omri_saadon

Reputation: 10631

Because your HealthEntry is not defined with self so basically he is locally to __init__ method.

change it to: self.HealthEntry

def __init__(self, parent):
        Tk.__init__(self, parent)
        self.parent = parent

        self.HealthEntry = Entry(self)

        testButton = Button(self, text = "entry field test", command = self.printHealth)
        testButton.grid(row=18, column=3)

def printHealth(self):
    Health = self.HealthEntry.get()
    print Health

As Padraic wrote in his answer, you might want to use testButton as a class member as well..

Upvotes: 2

Padraic Cunningham
Padraic Cunningham

Reputation: 180411

Make it an actual attribute and use self.HealthEntry, you might also want to do the same for testButton self.testButton:

        self.HealthEntry = Entry()    
        self.testButton = Button(self, text = "entry field test", command = self.printHealth)
        self.testButton.grid(row=18, column=3)

    def printHealth(self):
        Health = self.HealthEntry.get()
        print Health

To make it global and accessible outside the init method you would need to use the global keyword in the init method global HealthEntry but the correct way is to make it an attribute as above.

Upvotes: 1

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